Abstract: A heat pipe capable of being remarkably increased in service life by surely exerting sealing effect even under high temperature, and a method of manufacturing the heat pipe. A heat pipe remarkably reduced in cost by increasing productivity and capable of being increased in service life. In the heat pipe (1), an upper plate reinforcement part (50), intermediate plate reinforcement parts (52), reinforcement parts (55) with slits, and a lower plate reinforcement part (60) are fitted to each other in a steam diffusing flow passage (44) facing the peripheral areas of a refrigerant filling hole (4) and an air exhaust hole (5) to form a column structure.

Abstract: A heatsink is provided with a base body opposed to a heat generating body and absorbing heat from the heat generating body. Thermal resistance of that opposed portion of the base body which is opposed to the heat generating body is higher than thermal resistance of a surrounding portion surrounding the opposed portion.

Abstract: A heat pipe for cooling an exothermic body by the vaporization and condensation of an enclosed cooling medium is disclosed. The heat pipe comprises a flat plate-like upper plate, a flat plate-like lower plate opposed to the upper plate, and a plurality of flat plate-like intermediate plates overlaid on each other between the upper plate and the lower plate and having internal through-holes. The internal through-holes formed in each of a plurality of the intermediate plates are adapted such that only part of each through-hole is overlapped on each other to form capillary tube paths, each having a cross-sectional area smaller than the cross-sectional area of the through-hole in the flat surface direction.

Abstract: A small and thin heat pipe with enhanced heat conductivity. Between an upper member having a grid-like upper concave portion on an inside lower surface and a lower member having a grid-like lower concave portion on an inside upper surface are provided intermediate plate members. The members are each formed with multiple vapor diffusion flow paths extending in a planar direction, communicating with the concave portions of the members, respectively. Thus, a sealed space is defined therebetween so that a refrigerant is enclosed therein. Capillary flow paths are formed through a portion of the members except where the vapor diffusion flow paths are formed such that the capillary flow paths extend vertically or both vertically and horizontally, communicating with the concave portions of the members.

Abstract: Disclosed is an etching method of a laminated assembly having a metal layer and a non-thermoplastic polyimide layer bonded together via thermoplastic polyimide, which comprises using an etchant at least containing an alkali metal hydroxide, water and oxyalkylamine, wherein the concentrations of the alkali metal hydroxide (X weight %) and of the water (Y weight %) have relationships represented by coordinate points present within a region (inclusive of boundary lines) defined by the following expressions [1] and [2]: Y=(½)X (provided that 7≦X≦45)  [1] Y=({fraction (5/20)})X+17.5 (provided that 7≦X≦45)  [2] provided that X and Y are defined based on the total weight of the alkali metal hydroxide, water and oxyalkylamine expressed as 100.

Abstract: A multilayered circuit board for a semiconductor chip module includes an underlying board, insulating layers, fixed-potential wiring layers, via holes, and metal layers. The underlying board has a major surface made of a metal material to which a fixed potential is applied. The insulating layers are stacked on the major surface of the underlying board and have wiring layers formed on their surfaces. The fixed-potential wiring layers constitute part of the wiring layers formed on the insulating layers. The via holes are formed below the fixed-potential wiring layers to extend through the insulating layers. The metal layers are filled in the via holes so as to make upper ends be connected to the lower surfaces of the fixed-potential wiring layers. One of the insulating layers in contact with the major surface of the underlying board is formed on the underlying board while the lower end of the metal layer is in contact with the major surface of the underlying board.